4 * Implementation of the Domain-Based Mandatory Access Control.
6 * Copyright (C) 2005-2010 NTT DATA CORPORATION
11 #include <linux/kthread.h>
12 #include <linux/slab.h>
16 TOMOYO_ID_PATH_GROUP_MEMBER,
17 TOMOYO_ID_NUMBER_GROUP,
18 TOMOYO_ID_NUMBER_GROUP_MEMBER,
19 TOMOYO_ID_DOMAIN_INITIALIZER,
20 TOMOYO_ID_DOMAIN_KEEPER,
23 TOMOYO_ID_GLOBALLY_READABLE,
32 struct tomoyo_gc_entry {
33 struct list_head list;
37 static LIST_HEAD(tomoyo_gc_queue);
38 static DEFINE_MUTEX(tomoyo_gc_mutex);
40 /* Caller holds tomoyo_policy_lock mutex. */
41 static bool tomoyo_add_to_gc(const int type, void *element)
43 struct tomoyo_gc_entry *entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
47 entry->element = element;
48 list_add(&entry->list, &tomoyo_gc_queue);
52 static void tomoyo_del_allow_read
53 (struct tomoyo_globally_readable_file_entry *ptr)
55 tomoyo_put_name(ptr->filename);
58 static void tomoyo_del_file_pattern(struct tomoyo_pattern_entry *ptr)
60 tomoyo_put_name(ptr->pattern);
63 static void tomoyo_del_no_rewrite(struct tomoyo_no_rewrite_entry *ptr)
65 tomoyo_put_name(ptr->pattern);
68 static void tomoyo_del_domain_initializer
69 (struct tomoyo_domain_initializer_entry *ptr)
71 tomoyo_put_name(ptr->domainname);
72 tomoyo_put_name(ptr->program);
75 static void tomoyo_del_domain_keeper(struct tomoyo_domain_keeper_entry *ptr)
77 tomoyo_put_name(ptr->domainname);
78 tomoyo_put_name(ptr->program);
81 static void tomoyo_del_aggregator(struct tomoyo_aggregator_entry *ptr)
83 tomoyo_put_name(ptr->original_name);
84 tomoyo_put_name(ptr->aggregated_name);
87 static void tomoyo_del_alias(struct tomoyo_alias_entry *ptr)
89 tomoyo_put_name(ptr->original_name);
90 tomoyo_put_name(ptr->aliased_name);
93 static void tomoyo_del_manager(struct tomoyo_policy_manager_entry *ptr)
95 tomoyo_put_name(ptr->manager);
98 static void tomoyo_del_acl(struct tomoyo_acl_info *acl)
101 case TOMOYO_TYPE_PATH_ACL:
103 struct tomoyo_path_acl *entry
104 = container_of(acl, typeof(*entry), head);
105 tomoyo_put_name_union(&entry->name);
108 case TOMOYO_TYPE_PATH2_ACL:
110 struct tomoyo_path2_acl *entry
111 = container_of(acl, typeof(*entry), head);
112 tomoyo_put_name_union(&entry->name1);
113 tomoyo_put_name_union(&entry->name2);
116 case TOMOYO_TYPE_PATH_NUMBER_ACL:
118 struct tomoyo_path_number_acl *entry
119 = container_of(acl, typeof(*entry), head);
120 tomoyo_put_name_union(&entry->name);
121 tomoyo_put_number_union(&entry->number);
124 case TOMOYO_TYPE_PATH_NUMBER3_ACL:
126 struct tomoyo_path_number3_acl *entry
127 = container_of(acl, typeof(*entry), head);
128 tomoyo_put_name_union(&entry->name);
129 tomoyo_put_number_union(&entry->mode);
130 tomoyo_put_number_union(&entry->major);
131 tomoyo_put_number_union(&entry->minor);
134 case TOMOYO_TYPE_MOUNT_ACL:
136 struct tomoyo_mount_acl *entry
137 = container_of(acl, typeof(*entry), head);
138 tomoyo_put_name_union(&entry->dev_name);
139 tomoyo_put_name_union(&entry->dir_name);
140 tomoyo_put_name_union(&entry->fs_type);
141 tomoyo_put_number_union(&entry->flags);
145 printk(KERN_WARNING "Unknown type\n");
150 static bool tomoyo_del_domain(struct tomoyo_domain_info *domain)
152 struct tomoyo_acl_info *acl;
153 struct tomoyo_acl_info *tmp;
155 * Since we don't protect whole execve() operation using SRCU,
156 * we need to recheck domain->users at this point.
158 * (1) Reader starts SRCU section upon execve().
159 * (2) Reader traverses tomoyo_domain_list and finds this domain.
160 * (3) Writer marks this domain as deleted.
161 * (4) Garbage collector removes this domain from tomoyo_domain_list
162 * because this domain is marked as deleted and used by nobody.
163 * (5) Reader saves reference to this domain into
164 * "struct linux_binprm"->cred->security .
165 * (6) Reader finishes SRCU section, although execve() operation has
167 * (7) Garbage collector waits for SRCU synchronization.
168 * (8) Garbage collector kfree() this domain because this domain is
170 * (9) Reader finishes execve() operation and restores this domain from
171 * "struct linux_binprm"->cred->security.
173 * By updating domain->users at (5), we can solve this race problem
174 * by rechecking domain->users at (8).
176 if (atomic_read(&domain->users))
178 list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) {
180 tomoyo_memory_free(acl);
182 tomoyo_put_name(domain->domainname);
187 static void tomoyo_del_name(const struct tomoyo_name_entry *ptr)
191 static void tomoyo_del_path_group_member(struct tomoyo_path_group_member
194 tomoyo_put_name(member->member_name);
197 static void tomoyo_del_path_group(struct tomoyo_path_group *group)
199 tomoyo_put_name(group->group_name);
202 static void tomoyo_del_number_group_member(struct tomoyo_number_group_member
207 static void tomoyo_del_number_group(struct tomoyo_number_group *group)
209 tomoyo_put_name(group->group_name);
212 static void tomoyo_collect_entry(void)
214 if (mutex_lock_interruptible(&tomoyo_policy_lock))
217 struct tomoyo_globally_readable_file_entry *ptr;
218 list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list,
220 if (!ptr->head.is_deleted)
222 if (tomoyo_add_to_gc(TOMOYO_ID_GLOBALLY_READABLE, ptr))
223 list_del_rcu(&ptr->head.list);
229 struct tomoyo_pattern_entry *ptr;
230 list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, head.list) {
231 if (!ptr->head.is_deleted)
233 if (tomoyo_add_to_gc(TOMOYO_ID_PATTERN, ptr))
234 list_del_rcu(&ptr->head.list);
240 struct tomoyo_no_rewrite_entry *ptr;
241 list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list,
243 if (!ptr->head.is_deleted)
245 if (tomoyo_add_to_gc(TOMOYO_ID_NO_REWRITE, ptr))
246 list_del_rcu(&ptr->head.list);
252 struct tomoyo_domain_initializer_entry *ptr;
253 list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list,
255 if (!ptr->head.is_deleted)
257 if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN_INITIALIZER, ptr))
258 list_del_rcu(&ptr->head.list);
264 struct tomoyo_domain_keeper_entry *ptr;
265 list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list,
267 if (!ptr->head.is_deleted)
269 if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN_KEEPER, ptr))
270 list_del_rcu(&ptr->head.list);
276 struct tomoyo_aggregator_entry *ptr;
277 list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list,
279 if (!ptr->head.is_deleted)
281 if (tomoyo_add_to_gc(TOMOYO_ID_AGGREGATOR, ptr))
282 list_del_rcu(&ptr->head.list);
288 struct tomoyo_alias_entry *ptr;
289 list_for_each_entry_rcu(ptr, &tomoyo_alias_list, head.list) {
290 if (!ptr->head.is_deleted)
292 if (tomoyo_add_to_gc(TOMOYO_ID_ALIAS, ptr))
293 list_del_rcu(&ptr->head.list);
299 struct tomoyo_policy_manager_entry *ptr;
300 list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list,
302 if (!ptr->head.is_deleted)
304 if (tomoyo_add_to_gc(TOMOYO_ID_MANAGER, ptr))
305 list_del_rcu(&ptr->head.list);
311 struct tomoyo_domain_info *domain;
312 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
313 struct tomoyo_acl_info *acl;
314 list_for_each_entry_rcu(acl, &domain->acl_info_list,
316 if (!acl->is_deleted)
318 if (tomoyo_add_to_gc(TOMOYO_ID_ACL, acl))
319 list_del_rcu(&acl->list);
323 if (!domain->is_deleted || atomic_read(&domain->users))
326 * Nobody is referring this domain. But somebody may
327 * refer this domain after successful execve().
328 * We recheck domain->users after SRCU synchronization.
330 if (tomoyo_add_to_gc(TOMOYO_ID_DOMAIN, domain))
331 list_del_rcu(&domain->list);
338 for (i = 0; i < TOMOYO_MAX_HASH; i++) {
339 struct tomoyo_name_entry *ptr;
340 list_for_each_entry_rcu(ptr, &tomoyo_name_list[i],
342 if (atomic_read(&ptr->users))
344 if (tomoyo_add_to_gc(TOMOYO_ID_NAME, ptr))
345 list_del_rcu(&ptr->list);
354 struct tomoyo_path_group *group;
355 list_for_each_entry_rcu(group, &tomoyo_path_group_list, list) {
356 struct tomoyo_path_group_member *member;
357 list_for_each_entry_rcu(member, &group->member_list,
359 if (!member->head.is_deleted)
361 if (tomoyo_add_to_gc(TOMOYO_ID_PATH_GROUP_MEMBER,
363 list_del_rcu(&member->head.list);
367 if (!list_empty(&group->member_list) ||
368 atomic_read(&group->users))
370 if (tomoyo_add_to_gc(TOMOYO_ID_PATH_GROUP, group))
371 list_del_rcu(&group->list);
377 struct tomoyo_number_group *group;
378 list_for_each_entry_rcu(group, &tomoyo_number_group_list, list) {
379 struct tomoyo_number_group_member *member;
380 list_for_each_entry_rcu(member, &group->member_list,
382 if (!member->head.is_deleted)
384 if (tomoyo_add_to_gc(TOMOYO_ID_NUMBER_GROUP_MEMBER,
386 list_del_rcu(&member->head.list);
390 if (!list_empty(&group->member_list) ||
391 atomic_read(&group->users))
393 if (tomoyo_add_to_gc(TOMOYO_ID_NUMBER_GROUP, group))
394 list_del_rcu(&group->list);
399 mutex_unlock(&tomoyo_policy_lock);
402 static void tomoyo_kfree_entry(void)
404 struct tomoyo_gc_entry *p;
405 struct tomoyo_gc_entry *tmp;
407 list_for_each_entry_safe(p, tmp, &tomoyo_gc_queue, list) {
409 case TOMOYO_ID_DOMAIN_INITIALIZER:
410 tomoyo_del_domain_initializer(p->element);
412 case TOMOYO_ID_DOMAIN_KEEPER:
413 tomoyo_del_domain_keeper(p->element);
415 case TOMOYO_ID_AGGREGATOR:
416 tomoyo_del_aggregator(p->element);
418 case TOMOYO_ID_ALIAS:
419 tomoyo_del_alias(p->element);
421 case TOMOYO_ID_GLOBALLY_READABLE:
422 tomoyo_del_allow_read(p->element);
424 case TOMOYO_ID_PATTERN:
425 tomoyo_del_file_pattern(p->element);
427 case TOMOYO_ID_NO_REWRITE:
428 tomoyo_del_no_rewrite(p->element);
430 case TOMOYO_ID_MANAGER:
431 tomoyo_del_manager(p->element);
434 tomoyo_del_name(p->element);
437 tomoyo_del_acl(p->element);
439 case TOMOYO_ID_DOMAIN:
440 if (!tomoyo_del_domain(p->element))
443 case TOMOYO_ID_PATH_GROUP_MEMBER:
444 tomoyo_del_path_group_member(p->element);
446 case TOMOYO_ID_PATH_GROUP:
447 tomoyo_del_path_group(p->element);
449 case TOMOYO_ID_NUMBER_GROUP_MEMBER:
450 tomoyo_del_number_group_member(p->element);
452 case TOMOYO_ID_NUMBER_GROUP:
453 tomoyo_del_number_group(p->element);
456 printk(KERN_WARNING "Unknown type\n");
459 tomoyo_memory_free(p->element);
465 static int tomoyo_gc_thread(void *unused)
467 daemonize("GC for TOMOYO");
468 if (mutex_trylock(&tomoyo_gc_mutex)) {
470 for (i = 0; i < 10; i++) {
471 tomoyo_collect_entry();
472 if (list_empty(&tomoyo_gc_queue))
474 synchronize_srcu(&tomoyo_ss);
475 tomoyo_kfree_entry();
477 mutex_unlock(&tomoyo_gc_mutex);
482 void tomoyo_run_gc(void)
484 struct task_struct *task = kthread_create(tomoyo_gc_thread, NULL,
487 wake_up_process(task);